FLT3/NPM1 Gene Analysis with Interpretation

Label Mnemonic:	FLT3/NPM1
Epic code:	LAB5732
Downtime form:	A-1a Doctor/Provider Orders - Pathology Molecular

Molecular Pathology
6240 RCP
384-9568

Specimen(s):

Whole Blood

Collection Medium:

Pink top tube 6 mL (K2-EDTA)

Minimum:

3 mL of peripheral blood

Specimens for which the AML blast count is at least 10% will be tested.

Testing on smaller volumes may be attempted. However, this may compromise the ability to perform testing. Testing requires a dedicated collection tube.

Delivery Instructions:

Testing is generally not available on a STAT basis. However, expedited testing can be arranged by contacting the Molecular Pathology Laboratory at 384-9568 or the Molecular Genetic Pathology Fellow (pager #8682).

Testing Schedule:

0800-1700 Testing offered once per week excluding weekends and University holidays.

Turn Around Time:

7 working days

Reference Range:

Expected PCR fragment sizes for each DNA target are provided 
below for unaffected and affected samples.  The vast majority of 
affected persons harboring one or more of these mutations are 
heterozygous, meaning both products are present at the diagnostic 
locus.

             Unaffected       Affected
             (negative)      (positive)
 FLT3-ITD:     330 bp          >330 bp
 FLT3-D835:     67 bp           197 bp
 NPM1:         426 bp           430 bp

Comments:

FLT3 and NPM1 Mutation Detection Assays test for two different mutations in the FLT3 gene and an insertion in exon 12 of the NPM1 gene, all of which are somatic mutations associated with acute myelogenous leukemia (AML). These molecular markers are useful in diagnosis and clinical stratification of AML patients. Detection of FLT3 in-frame internal tandem duplications (FLT3-ITD mutation) is performed as a mail-out test (sent to a reference laboratory), whereas the assays that detect FLT3 point mutations that alter the aspartic acid at position 835 (FLT3-D835) and the NPM1 mutations are performed in the University of Iowa Molecular Pathology Laboratory. To avoid confusion, the results for all 3 targets are reported together in a consolidated interpretation.

Methodology:

Multiplex PCR followed by Eco RV digestion with fluorescent fragment analysis on the ABI 3130 (capillary electrophoresis).

CPT Code:

81245, 81246, 81310